The classic Voisin
pusher biplane design of 1907 was one of the most significant aircraft
of the pre-World War I era. Many of Europe's leading aviators flew the
Voisin. On January 13, 1908, Henri Farman made the first one-kilometer
circuit in Europe with a Voisin biplane, winning a 50,000-franc prize
and much acclaim for the Voisin product. By 1912, Les Frères Voisin had
produced more than 75 airplanes that were based on the simple and
sturdy 1907 design.
In 1912, the Voisin
brothers developed a version of their successful design for the
military. Thereafter they built aircraft almost exclusively for
military contracts. The Voisin 1912 Type, as it was referred to by the
French military, also sometimes identified as the Voisin Type 1,
launched the standard configuration of almost all Voisin aircraft
throughout the war. Designated the Type L by the Voisin factory, this
seminal airplane was an equal-span biplane with no dihedral, with a
short nacelle carrying the crew of two in front and an 80-horsepower Le
Rhône 9C engine at the rear. A cruciform tail was attached to the wings
with a set of booms, and it had a quadricycle landing gear. A second
pre-war military design, similar to the Type L, powered by a
70-horsepower Gnome 7A engine, was produced in 1913. Although they were
largely obsolete by the start of the war, the sturdiness and the
reliability of these, and subsequent, Voisin aircraft enabled them to
form the backbone of the French night bomber force until late in 1918.
Les Frères Voisin was
conservative in its design philosophy. There were only slight,
incremental design changes in the airframes during the war. Improvement
in performance of the successive types was made principally by
installing more powerful engines, usually necessitating wings of
greater span. The first wartime version, the Voisin 3, powered by a
120-horsepower Salmson M9 engine, had a range of 200 km (125 mi),
carrying a bomb load of 150 kg (330 lb). The 1918 Voisin 10 by
comparison, which in outward appearance looked much like the Voisin 3,
had a range of 350 km (220 mi) with a bomb load of 300 kg (660). The
280-horsepower Renault 12Fe engine of the Voisin 10 gave it a maximum
speed of 135 kph (84 mph) at 2,000 m (6,562 ft) altitude, 37 kph (23
mph) faster than the Voisin 3 at the same altitude.
During the war, the
Voisin pusher series performed a variety of missions, including
reconnaissance, artillery spotting, training, day and night bombing,
and ground attack. The first recorded armed aerial victory of the war
occurred on October 5, 1914, when a French pilot and his observer,
flying a Voisin 3, downed a German Aviatik B.1 with bullets fired from
a Hotchkiss machine gun.
The Voisin 3 is also
notable in having equipped the first dedicated bomber units. Voisin 3
units staged a retaliatory attack against the Badische Anilin
Gesellschaft at Ludwigshaven, Germany, on May 26, 1915, shortly after
the German Army introduced poison gas in battle. Successful daytime
attacks on targets within Germany ensued, but by 1916 the Voisin 3 and
its immediate successors became vulnerable to new, better performing,
German fighters. (The Voisin Type 4 was similar to the Type 3, but was
fitted with a 47 mm cannon and used primarily for ground strafing. The
Types 5 and 6 were virtually the same as the Type 3, except that they
had more powerful Salmson engines.) The Voisins were slow and with
their pusher configuration they were defenseless from the rear. Despite
these limitations, these rugged and reliable aircraft still had a role
to play. Voisins were used as trainers and for night missions for the
remainder of the war. Voisin pusher aircraft were supplied to, or built
under license by, twelve countries, including Britain, Russia, Italy,
and the United States.
The Voisin Type 8
entered service with French night bombing squadrons in November 1916.
(The Type 7 was a transitional model of which only about a hundred were
built.) The Type 8 was intended to be powered by a 300-horsepower
Hispano-Suiza engine, nearly double the output of the 155-horsepower
Salmson used on the Type 6. But the Hispanso-Suizas were not available
in sufficient numbers, and a 220-horsepower Peugeot 8 Aa inline was
substituted. To accommodate the bulkier and heavier Peugeot, the Type 8
required an enlarged and strengthened fuselage, and greater wingspan.
It was fitted with either a single machine gun or a 37 mm cannon.
The new engine provided
a nominal increase in performance over the Voisin Type 6 while carrying
the same bomb load of 180 kg (396 lb); but it was unreliable. Voisin
then developed the Type 10, which combined a lighter and more powerful
280-horsepower Renault 12Fe engine with the Type 8 airframe. The Type
10, with improved range, speed, and bomb load, replaced the Voisin Type
8 early in 1918. (Only one Type 9 was built. It was a modified Type 8
with 160-horsepower 8G engine intended for reconnaissance.)